Liquid waste feed system

ABSTRACT

A pressurized liquid waste tank feeds liquid waste into liquid waste processing equipment. The processed liquid is pumped into an accumulator tank which has an actuator that opens and closes microswitches as the accumulator tank is filled and emptied. These microswitches control solenoid valves which are located in the lines feeding the liquid waste processing equipment, the accumulator tank and the collecting tank. An electrical circuit ties together the switches and valves in a manner such that sufficient waste liquid is automatically maintained in the liquid waste processing equipment to give optimum system performance in a zero gravity environment.

United States Patent Hall, Jr. et al.

[ 51 June 20, 1972 [54] LIQUID WASTE FEED SYSTEM [72] Inventors: John B.Hall, Jr.; Y1 'lung, both of Newport News; Lavern E. Winn, Hampton, allof Va.

[73] Assignee: The United Statw 01 America as represented by theAdministrator of the National Aeronautics and Space A dmlnis: tration[22] Filed: Jan. 15, 1970 [21] Appl.No.: 3,151

[52] U.S.Cl ..2l0/104,2l0/103,210/110, 210/137 [51] Int. Cl ..B0ld 43/00[58] Field ofSearch ..210/98,l03,104, 110,111, 210/128, 137, 167

[56] References Cited illfllTEl) STATES PATENTS 1,691,862 11/1928Thompson et al. ..210/98 III .JH

Primary Examiner-John Adee Attorney-Howard J. Osborn and G. T. McCoy[57] ABSTRACT A pressurized liquid waste tank feeds liquid waste intoliquid waste processing equipment. The processed liquid is pumped intoan accumulator tank which has an actuator that opens and closesmicroswitches as the accumulator tank is filled and emptied. Thesemicroswitches control solenoid valves which are located in the linesfeeding the liquid waste processing equipment, the accumulator tank andthe collecting tank. An electrical circuit ties together the switchesand valves in a manner such that sufficient waste liquid isautomatically maintained in the liquid waste processing equipment togive optimum system performance in a zero gravity environment.

9 Clalns, 4 Drawing Figures WASTE LIQUID x13 WASTE WATER PROCESSINGEQUIPMENT COLLECTING TANK PRESSURE III PATENTEDmzo I972 3,670,890

SHEET 1 or 2 p viiis WASTE WATER PROCESSING /22 EQUIPMENT 42 26 PUMPPRESEUYE V63 32*- x3| I:

"-3 NO IN 0 0L ECT N6 49 50 c L I TANK 48 INVENTORS 4 JOHN B. HALL, JR.

Yl TUNG BY LAVERN E. wmn 30 A S /'ATTORNEYS PATENTEDJUHZO m2 3,670 690SHEET 2 OF 2 FIG. 2

WASTE -68 FIG. 3 v 70 LIQUID 92 X INNNO c as )7 g WASTE WATER 89PROCESSING 90 EQUIPMENT PUMP W78 IN No 95 COLLECTING TANK 94 INVENTORSJOHN B. HALL, JR. Yl TUNG BY LAVERN E. WINN LIQUID WASTE FEED SYSTEMORIGIN OF THE INVENTION The invention described herein was made byemployees of the United States Government and may be manufactured andused by or for the Government for governmental purposes without thepayment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION AND PRIOR ART Various techniques have beenutilized to maintain sufficient waste liquid in liquid waste processingequipment. One such technique is the use of pressure, temperature orhumidity sensors placed in the liquid waste processing equipment. Thesesensors which are normally set for sensing constant parameters respondto the transient conditions occurring in the processor due to solidsbuildup as the waste liquids are processed. Although such a system isoperable to a degree, the use of sensors usually results in eitherflooding the waste processing equipment or operation of the system toodry for efficient water recovery from the liquid wastes.

Another technique utilized is that of timers to actuate the feedcircuits to the liquid waste processing equipment. The use of suchtimers requires a constant waste water processing rate. However, theprocessing rate will change with either solid buildup in the processoror a change in operating parameters. Since a water recovery system on anextended space mission usually will not operate according to constanttimes and parameters, it is apparent that the use of timers will notsatisfy the requirements for an operable system.

SUMMARY OF THE INVENTION The present invention overcomes theabove-mentioned difficulties by providing a feed system which basicallyconsists of a feed circuit and a sensing circuit to control the flow ofwaste liquids to and from the processing equipment. The feed system iscontrolled by valves which permit the liquid waste to flow from a supplysource to the waste water processing equipment. The processed water isthen pumped into an accumulator which actuates the sensing circuit. Whensufficient processed liquid has been collected in the accumulator, thevalves are operated to discharge the processed liquid into a collectingtank. The sensing circuit at this time also actuates valves whichprovide the liquid waste processing equipment with a new supply of wasteliquid, initiating a new cycle. With proper adjustment of the valves andthe sensing microswitches, the right amount of liquid waste is alwaysavailable to the liquid waste processing equipment to enable it tooperate at optimum efficiency. Such an arrangement also providesequipment which will operate efficiently and reliably in a zero gravityenvironment. Since the supply of liquid waste to the processingequipment is dependent on the amount of liquid actually processed, theentire system is automatically selfregulating providing an optimumarrangement for use over an extended period of time.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view showing thevarious components of the liquid waste feed system;

FIG. 2 is a schematic view of the electrical circuit utilized to controlthe components of the liquid waste feed system;

FIG. 3 is a diagrammatic view of a modified form of liquid feed system;and

FIG. 4 is a cross sectional view of an accumulator tank modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the details ofthe invention, the reference numeral designates generally the inventionwaste feed system as shown in FIG. 1.

The supply tank 11 provides a storage means for the liquid waste. Theliquid waste may come from various sources, and would be collected andpiped to the tank in a spacecraft or space station which would beutilizing liquid waste processing equipment for the recovery of water orother liquids from the waste. The tank 11 contains a pump 12 or someother device for creating pressure within the tank. Liquid waste 13 isshown as being at some level in the tank 11. The conduit 14 is connectedto the liquid waste processing equipment 22. Located in the conduit 14between the supply tank and the processing equipment is a solenoid valve15 having a normally closed port NC and an open port IN. A throttlingvalve 16 is also connected into the conduit 14. The purpose andoperation of these valves will be explained in greater detailsubsequently. The liquid waste processing equipment 22 may be for thepurpose of recovering potable water from liquid waste or other liquidsfrom waste. Various types of this equipment are known and therefore theparticular details of the equipment need not be explained.

A discharge conduit 25 connects the liquid waste processing equipmentwith solenoid valve 27 which has a normally closed port NC, a normallyopen port NO, and an open port IN. The purpose of solenoid valve 27 willbe explained more fully subsequently. A pump 26 is located in line 25and is utilized to pump the processed liquid out of the processingequipment to the solenoid valve 27.

A conduit 30 connects the solenoid valve 27 with an accumulator tank 31.A piston 32 is located within the accumulator tank 31 and is movableunder the influence of processed liquid which is conveyed from theprocessing equipment via conduit 25 through the solenoid valve 27 andconduit 30. Connected to the piston 32 is a rod 33 which projectsthrough the top surface of the tank. A switch trigger 34 is connected tothe end of the rod 33 and is movable in a guide 35 which is attached tothe accumulator tank. A switch post 36 is also connected to theaccumulator tank and carries rnicroswitches 37 and 38. The microswitch37 is positioned adjacent the top of the rod and the microswitch 38adjacent the top of the accumulator tank. The switches 37 and 38 haveprojections which are encountered by the movement of the switch trigger34 to open and close the switches for reasons which will be explained indetail subsequently. A pressure tank or source of pressure 42 is locatedadjacent the accumulator tank 31 and has a conduit 43 which connectswith the accumulator tank 31. A solenoid valve 44 is located in conduit43 and controls flow of pressure into the accumulator tank for movingpiston 32 to discharge processed liquid from the accumulator tank. Thesolenoid valve 44 has a normally closed port NC, an open port IN, and anormally open vent port NO.

A modified form of accumulator tank is shown in FIG. 4 and is designatedgenerally by the reference numeral 45. The accumulator tank 45 isspherical and contains a flexible diaphragm 46. A rod 47 is connected tothe diaphragm 46 and projects through the top of the tank. The tankwould connect to the conduits 43 and 30 similar to the accumulator tank31. The rod 47 would have a switch trigger similar to 34 to actuate themicroswitches.

A collecting tank 50 is connected by conduit 48 to the solenoid valve27. The collecting tank 50 receives processed liquid discharged from theaccumulator tank 31. A throttling valve 49 is located in conduit 48operates to control the time required to expel the processed water fromthe accumulator tank 31 to the collecting tank 50.

The electrical circuit designated generally by the reference numeral 55utilized in controlling the various components of the feed system isshown in FIG. 2. A power supply 56 is provided in the form of a batteryor some other similar device. Microswitches 37 and 38 are positioned inparallel with the power supply. A relay coil 58 is in series withmicroswitch 37 and a relay coil 59 is positioned in series withmicroswitch 38. The relay coils are linked to switch contacts 61 whichare positioned in series with the solenoid valves 15, 27 and 44. Theswitch contacts and solenoid valves as a unit are placed in parallelwith the power supply and other components of the system.

An alternate embodiment of the invention is shown in FIG. 3 anddesignated generally by the reference numeral 65. In this embodiment ofthe invention, the supply tank 66 contains liquid waste 68 which isplaced under pressure by a pump or other source of pressure 67. Thesupply tank 65 is connected to a solenoid valve 70 by the line 69. Thesolenoid valve 70 has a normally open port NO, a nonnally closed portNC, and an open port IN. Another line 71 connects the solenoid valve 70with the liquid waste processing equipment 75. The liquid wasteprocessing equipment 75 is similar to the equipment 22 discussed withregard to the previous embodiment. A discharge line 77 connects theliquid waste processing equipment with another solenoid valve 80. Thisvalve also has a normally closed port NC, a normally open port NO, andan open port IN. A pump 78 is located in the discharge line and isutilized to pump liquid from the processing equipment to the solenoidvalve 80.

A lower accumulator line 82 connects the solenoid valve 80 with theaccumulator tank 84. The accumulator tank 84 houses a double endedpiston arrangement having heads 85 and 87 with an intermediateconnecting rod 86. A bracket 88 fixed to the accumulator tank 84 carriesmicroswitches 89 and 90. The microswitches have fingers which areactuated by the piston heads 85 and 87 to open and close the switches.An upper accumulator line 92 connects the other side of the accumulatortank 84 with the solenoid valve 70.

A collecting tank line 94 connects the solenoid valve 80 with collectingtank 95.

The electrical circuit shown in FIG. 2 may be utilized to control thefeed system embodiment 65; therefore, the explanation of another circuitis not considered necessary.

OPERATION In operation, the supply tank or storage tank 11 containswaste liquid which has been collected by means of a waste collectingsystem. The liquid waste processing equipment is also filled to thedesired capacity to initiate operation. The liquid waste processingequipment is activated together with the pump 26 and as the liquid isprocessed, it is pumped through the conduit 25 to the solenoid valve 27.The solenoid valve port connected with the line 25 is normally open,allowing the processed liquid to be conveyed through the conduit 30 tothe accumulator tank 31.

As the accumulator tank 31 is filled with processed liquid, it will beapparent that piston 32 is forced in an upward direction. Any air whichmight be trapped on the top side of the piston is vented through thesolenoid valve 44 port vent. The accumulator tank fills until the pistonand its rod assembly moves to the vicinity of microswitch 37. The switchtrigger 34 then closes microswitch 37 which completes a circuit to therelay coil 58 (FIG. 2). The relay coil 58 will move the switch contact61 from the NC position to the NO position completing a circuit to thesolenoid valves 15, 27 and 44. The normally closed solenoid valve isthereby opened allowing the waste liquid in the supply tank 11 to flowinto the liquid waste processing equipment 22. The amount of flow can beregulated by the throttling valve 16.

At the same time, the normally closed solenoid valve 44 is openedallowing pressure from source 42 to enter the top side of theaccumulator tank 31 via the conduit 43. The pressure on the top side ofthe piston causes it to move down forcing processed liquid out of theaccumulator tank into conduit 30. Normally opened solenoid valve 27 isclosed when the solenoid valves 15 and 44 are opened thus preventingprocessed water from conduit 25 to pass through the valve 27, butallowing the processed water 30 being discharged from the accumulatortank 31 to pass through the valve 27 into the conduit 48 and to thecollecting tank 50. The throttling valve 49 may be utilized to controlthe rate of flow from the accumulator tank to the collecting tank 50. Itis apparent from the discussion thus far that the throttling valves 16and 49 may be used in conjunction to provide a balance for the feedsystem.

When the piston 32 bottoms in the accumulator tank 31, the switchtrigger 34 will actuate microswitch 38 which will activate relay coil 59(FIG. 2). This will cause switch contact 61 to move to the NC positionopening the circuit to solenoid valves 15, 27 and 44. Solenoid valve 15will then assume its normally closed position preventing waste liquidfrom passing out of the supply tank 11 into the waste water processingequipment 22. Solenoid valve 27 will assume its normally open positionallowing the processed liquid from the processing device 22 to passthrough the valve into the accumulator tank 31. The solenoid valve 27will also close the passage to conduit 48 and the collecting tank 50.The solenoid valve 44 will assume its normally closed position ventingthe top side of the accumulator tank 31. The feed system then recyclesas described and continues to recycle in a manner which automaticallymaintains the proper amount of liquid waste in the liquid waste waterprocessing equipment.

The operation of the alternate liquid waste feed system 65 shown in FIG.3 is similar to that of the system 10; however, it differs somewhat inthat the system is a simpler design. As with system 10, the liquid wasteprocessing equipment 75 is initially charged with a sufficient quantityof waste liquid. Since solenoid 70 is normally open, and the wasteliquid in supply tank 68 is under pressure, the top side of theaccumulator tank 84 is also filled via the line 92.

As the water is processed, it is pumped via the conduit 77 through pump78 into the solenoid valve 80. The nonnally opened portion of solenoidvalve 80 allows the processed liquid to flow into line 82 and the bottomside of the accumulator tank 84. When the piston 85 moves a sufficientdistance, the appropriate microswitch is energized making a circuit tothe relay coil which closes the switch contact on the solenoid valvesclosing the normally open ports and opening the normally closed ports.The processed liquid is then forced out of the bottom side of theaccumulator tank 84 into the line 82 through the solenoid valve 80 intothe line 94 and to the collecting tank 95. This is accomplished by thepressurized liquid waste from supply tank 65 operating on the piston 87in the top side of the accumulator tank 84. When the processed liquidwater has been discharged from the accumulator tank 84, the piston 87will have reached a point to actuate the appropriate microswitch andactivate a relay which closes the switch contacts on the solenoid valvesand returns them to their normally open and closed positions. The cyclethen repeats itself and continues to repeat itself to provide the properamount of waste liquid to the liquid waste processing equipment.

The electrical circuit shown in the FIG. 2 is utilized to control themodified waste system 65. However, since only two solenoid valves areutilized, one of the valves would be eliminated from the circuit. Sincethe circuits are essentially identical for both embodiments, a detaileddescription of a circuit for the FIG. 3 embodiment has been eliminated.Although not shown in the FIG. 3 embodiment, it is to be understood thatthrottling valves may also be utilized in the lines leading to theliquid waste processing equipment and the collecting tank as in the FIG.1 embodiment.

The device is believed to have a decided advantage over the prior art inthat the system is not dependent on process rates nor rely on constantconditions within the processing equipment to initiate the liquid feedcircuit. The quantity of waste liquid required in the processor foroptimum performance can be maintained by the control circuit such thatessentially the quantity of water processed from the system is replacedby an equal or additional amount of waste liquid. The system is highlyreliable, has few components and working parts providing a generallymaintenance-free system. The feed system is also particularly adapted tooperation in the zero gravity environment without being subject to thevarious parameters which affect such as environment.

It is to be understood that the foregoing disclosure relates only topreferred embodiments of the invention and that numerous modificationsand variations of the present invention are possible in the light of theabove teachings without departing from the spirit or scope of theinvention as set forth in the appended claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

l. A waste liquid feed system comprising: means for containing wasteliquid under pressure; means for pressurizing said means for containingwaste; waste liquid processing means; means for collecting processedwaste liquid; means to automatically maintain sufficient liquid in saidliquid processing means in a zero gravity environment includingaccumulator means; actuator means positioned in said accumulator meansopenable by processed liquid flow in said accumulator means; and valvemeans controlled by said actuator means in lines providing fluidcommunication between said means for containing waste liquid, saidliquid processing means, said accumulator means, and said collectingtank means to give optimum performance in a zero gravity environment. 2.A waste liquid feed system as in claim 1 wherein switch means isassociated with said actuator means for opening and closing said valvemeans, and electrical circuit means for controlling said switch meansand valve means.

3. A waste liquid feed system as in claim 2 wherein said actuator is apiston and rod.

4. A waste liquid feed system as in claim 2 wherein said actuator is adiaphragm.

S. A waste liquid feed system as in claim 1 wherein said valve meansincludes a first solenoid valve between said means for containing liquidand said liquid processing means; a second solenoid valve between asource of pressure and said accumulator tank means; and a third solenoidvalve between said waste liquid processing equipment and saidaccumulator tank means and collecting tank means.

6. A waste liquid feed system as in claim 1 wherein said valve meansincludes a first throttling valve at the input of said waste liquidprocessing equipment; and a second throttling valve at the input of saidcollecting tank means.

7. A waste liquid feed system as in claim 1 wherein said accumulatortank means includes an actuator; a first solenoid valve located at theoutput of said means for containing liquid waste and regulating flow tosaid waste liquid processing equipment and to one side of saidaccumulator tank actuator means; and a second solenoid valve locatedbetween said waste liquid processing equipment and said accumulator tankmeans and collecting tank means; said second solenoid valve regulatingflow to the other side of the actuator means and to said collecting tankmeans.

8. A waste liquid feed system as in claim 7 wherein switches areassociated with said actuator means; said switches being opened andclosed by movement of said actuator means and controlling said first andsecond solenoid valve.

9. A waste liquid feed system as in claim 7 wherein pump means drawsprocessed liquid out of said processing equipment and pumps it into saidaccumulator tank means and said collecting tank means.

1. A waste liquid feed system comprising: means for containing wasteliquid under pressure; means for pressurizing said means for containingwaste; waste liquid processing means; means for collecting processedwaste liquid; means to automatically maintain sufficient liquid in saidliquid processing means in a zero gravity environment includingaccumulator means; actuator means positioned in said accumulator meansoperable by processed liquid flow in said accumulator means; and valvemeans controlled by said actuator means in lines providing fluidcommunication between said means for containing waste liquid, saidliquid processing means, said accumulator means, and said collectingtank means to give optimum performance in a zero gravity environment. 2.A waste liquid feed system as in claim 1 wherein switch means isassociated with said actuator means for opening and closing said valvemeans, and electrical circuit means for controlling said switch meansand valve means.
 3. A waste liquid feed system as in claim 2 whereinsaid actuator is a piston and rod.
 4. A waste liquid feed system as inclaim 2 wherein said actuator is a diaphragm.
 5. A waste liquid feedsystem as in claim 1 wherein said valve means includes a first solenoidvalve between said means for containing liquid and said liquidprocessing means; a second solenoid valve between a source of pressureand said accumulator tank means; and a third solenoid valve between saidwaste liquid processing equipment and said accumulator tank means andcollecting tank means.
 6. A waste liquid feed system as in claim 1wherein said valve means includes a first throttling valve at the inputof said waste liquid processing equipment; and a second throttling valveat the input of said collecting tank means.
 7. A waste liquid feedsystem as in claim 1 wherein said accumulator tank means includes anactuator; a first solenoid valve located at the output of said means forcontaining liquid waste and regulating flow to said waste liquidprocessing equipment and to one side of said accumulator tAnk actuatormeans; and a second solenoid valve located between said waste liquidprocessing equipment and said accumulator tank means and collecting tankmeans; said second solenoid valve regulating flow to the other side ofthe actuator means and to said collecting tank means.
 8. A waste liquidfeed system as in claim 7 wherein switches are associated with saidactuator means; said switches being opened and closed by movement ofsaid actuator means and controlling said first and second solenoidvalve.
 9. A waste liquid feed system as in claim 7 wherein pump meansdraws processed liquid out of said processing equipment and pumps itinto said accumulator tank means and said collecting tank means.